A Geneva drive is a two-geared mechanism which turns a continuous rotation into an intermittent rotary motion, thus producing very precise ticks forward. It was developed by Swiss watchmakers, and is still used today in movie projectors, the machines that banks use to count money, and even this cool 3D printed Stargate mechanism. But now, bioengineers at Columbia University have created a 15-millimeter Geneva drive, using squishy hydrogel, in order to make a biocompatible micromachine that can be used to deliver doses of drugs on command once it’s been implanted inside your body. Think about it – you wouldn’t have to keep watching the clock to determine if it’s time for your next dose yet! The device was created in the Sia Lab, where the principal investigator, Columbia University professor of biomedical engineering Samuel Sia, spends his days working with microfluidics.
The Geneva drive micromachine doesn’t utilize batteries or wires: these drives traditionally work by adding a driven wheel to the gear, which has slots, and advances a single step of 90° each time the wheel rotates. Sia’s micromachine platform, formally titled “implantable microelectromechanical systems (iMEMS),” can be used to deliver a dose of medicine on command, and is controlled from outside the body. This way, doctors who prescribe the medicine are able to see how their patient is faring, and then modify any medicinal therapy if necessary. Sia has already tested the iMEMS in lab mice with osteosarcoma (bone cancer), and the positive results were published yesterday in the Science Robotics journal. The abstract for the experiment explains that by “exploiting the unique mechanical properties of hydrogels, we developed a locking mechanism for precise actuation and movement of freely moving parts.”
The video below shows how the iMEMS works.